This disclosure relates to a method for identifying individual animals. It is applicable to fur-bearing animals having distinctive trichoglyphs or cowlicks at identifiable positions on the body of the animal. While it will be described specifically in relation to identification of horses, it is to be understood that the disclosue is applicable to many other animals as well.
Reliable identification of animals assists in establishing proper health and animal care programs, issuance of regulatory certificates and accurate establishment of genetics-based breeding programs. Accurate identification also is important in proving ownership of the animal, in proving the nature of fraudulent markings applied to the animal, and in assisting the owner in claiming a stolen animal after it is recovered. In the particular case of animals having high monetary value, an identification system must further be unalterable, or must use identifying determinants which cannot be altered without the alteration being obvious.
While no single animal identification system is in itself perfect or totally reliable, there is need for a system having universal applicability, using visual markings which remain unchanged over the life of the animal and which makes alterations easily detectable.
The present description meets these standards by utilization of natural trichoglyphs or "cowlicks" as visual markings. An impression is made of at least one trichoglyph, and its location with respect to externally recognizable anatomical features of the animal is registered by markings provided on the impression as it is being made. The final impression can then be related to a grid indexed to identifiable features on the body of the horse. Significant features of the trichoglyph pattern can be plotted with respect to this grid to reduce identification of the trichoglyph pattern to a two dimensional mathematical statement for recording and data storage and retrieval at a later date.
Trichoglyphs are currently being used in at least two other species for identification. Zoologists at the U.S. Fish and Wildlife Service have studied the distribution of hairs in seals. It is reported that hair arrangement, size, and distribution are distinct for various genera of seals. With the skin fragments recovered from the stomachs of whales and sharks, investigators hope to identify which genus of seal is being preyed upon most heavily.
Even more interesting is the use of hair whorls for animal identification in the Far East. In the rice lands of Asia, the water buffalo is a valued beast of burden. They are treated with care and consideration. Religion and philosophy prohibit any form of animal identification that involves mutilation, and, therefore, tattooing and branding are not used. Until recently, traditional beliefs restricted the use of ear tags in livestock. In this part of the world the location of hair whorls are accepted as a means of livestock identification. It is reported that hair whorls are distinct for each individual water buffalo and have a legal basis for identification in Malaysia and the Philippines.
It is generaly agreed that hair slope and direction is determined in the early embryo. At this time, the individual hair is forming in the layer of skin termed the epidermis. To become fully developed, the hair must grow down to the underlying dermis and become anchored as the hair bulb. Concurrently, the underlying muscles and bones are growing and placing various planes of stretch on the skin. The plane of stretch will determine the direction of the hair. This theory proposed only recently with respect to the origin of hair whorls, explains why trichoglyphs are consistently seen in certain regions of the body.
One type of trichoglyph, the hair whorl, is created when the skin is stretched around prominences that occur in the early embryo. The frontal hair whorl on the head of the horse corresponds to the cowlick on the scalp of most people. The human embryo has a cranial dome around which the skin is stretched to produce the typical cowlick. In the developing equine embryo, there are several areas of the head that protrude to produce the frontal hair whorl. This variety in the shape of the skull of the early equine embryo results in the great many types of frontal whorls seen.
Once the trichoglyph is established, it is permanent and unalterable. This has been shown by experiments done on laboratory mice and guinea pigs in which surgical rotation of portions of skin did not alter original pattern or direction of the trichoglyph.
If one accepts the above theory as to development of trichoglyphs, it will be recognized that there is no primary genetic control of trichoglyphs, i.e., there are no genes that code for a specific type of trichoglyph. Therefore, one must conclude that the genetic make up of the animal determines its early embryonic form and the trichoglyphs that result are secondary to the stresses placed on the skin by the shape of the earyl embryo. Each trichoglyph is therefore unique to an individual animal.
The present disclosure is based upon the premise that a trichoglyph can serve as an accurate means for proving the identity of an animal. The use of trichoglyphs for identification purposes does away with the need for brands, lip tattoos and other markings which are sometimes objectionable as being cruel, unsightly and readily alterable.
Trichoglyphs are more reliable as visual determinants because of their permanence. Even surgical removal in the area of the trichoglyph leaves the surrounding hair pattern unchanged, making alterations easily detectable. A trichoglyph can be compared to fingerprints so far as visual determinants are concerned. In most cases, each is different. However, in the unlikely case of two animals having identical trichoglyphs, other characteristics such as age, color, size, markings and sex would no doubt differentiate the particular animals.
This disclosure is concerned with an effective system for recording the nature and accurate position of trichoglyphs for identification of an animal.